Turns out the subtle difference other than the privileges SYSTEM vs USER is in the libraries you can include, this drastically affects what you can achieve in each type of driver.
With KMDF you can #include
ntddk.h allows you to register callbacks to;
The drawback to not being allowed to use windows.h is when I try to perform hashing of files, objects or strings etc, I am able to reference the likes of
Ultimately the question is, should I do this in the KMDF as any error will result in a bluescreen, so really I should be looking to do bare minimum with very high level of error control to prevent BSOD. Will the delay in ferrying data between drivers be a problem?
Now looking back at UMDF2.0 you can #include
So by using KMDF to monitor all activities, pass data to UMDF2.0 for hashing and reputation checks, wait for verdict, then block or allow activity. We can create our own application control which can later be expanded upon to perhaps perform multi-vendor sandbox submissions, or compare hash database against others sources such as www.nsrl.nist.gov (handy for verifying the integrity of your OS, often used in forensics for eliminating common and known files)
That’s all for now